Method of treating cork



Patented Dec. 26, 1922.

UNITED STATES WILLIAM E. C0 HAGA N, 0F DENVER, COLORADO.

METHOD OF TREATING CORK.

Application filed December 12, 1921.

To all whom Jim/1y concern.

Be it known that I. IVILLIAM E. Co HA- oAN, a citizen of the United States, residing at the city and county of Denver and State of tolorado. have invented certain new and useful Improvements in Methods of Treating Cork; and I do declare the following to be a full. clear, and exact description of the invention. such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings. and to the characters of reference marked thereon, which form a part of this specification.

This invention relates to a method and an apparatus for treating cork so as to make it non-absorbtive of water and water vapors, and to increase its density without destroying its resiliency.

In Patent No. 1.38.5,508, granted to Lou J. Trembley on July 26. 1921, there is described and claimed a piston ring in which a cork liner is employed between the inner surface of the ring and the bottom of the groove in the piston; this cork cooperates with certain projecting portions on the inner surface of the ring, and serves to make an effective oil and gas seal. In installing piston rings in accordance with the teaching of the above patent, it is found that unless the cork is compressed to the desired size and shape before it is put into place. it is diiiicult to insert the pistons into the cylinders as the cork tends to hold the rings expanded, and this necessitates the use of a powerful compressor for holding the rings in contracted form until they have been inserted into the cylinder. Even when the pistons are finally gotten into place in the cylinder, the pressure due to the compressed cork is so great that the pistons work hard, and only after the engine has operated for some time will the pistons move freely.

In order to overcome the difiiculties just pointed out. I compress the cork in a suitable mould'so as to make it into the exact shape and size desired. I find, however, that un less I subject the cork to the action of some moisture repellent material. and to a degree of heat substantially equal to or greater than that to which it will be subjected in actual operation, that difficulties will still be experienced, especially where the compressed cork is sent into damp climates, as the cork seems to absorb moisture from the air and Serial No. 521,773.

swell, thus gradually losing the shape and size to which it was compressed.

In order to more clearly describe my invention or discovery, I shall have reference to the accompanying drawing in which Fig. 1 shows a fragment of a, piston equipped with my improved cork liner. the ring and cork liner being shown in section;

Fig. 2 is a plan view of a strip of treated cork;

Fig. 3 is a transverse section taken on line 3-3, Fig. 2;

Fig. 4 is a transverse section of a strip of cork showing its appearance before it has been subjected to treatment;

Fig. 5 is a plan view of the female part of my mould;

Fig. 6 is an end view of the mould shown in Fig. 5;

Fig. 7 is a longitudinal section taken on line 7-7, Fig. 5; and

Fig. 8 is a transverse section showing my mould in operation.

The same reference numerals will be used to indicate the same parts throughout the several views.

In Fig. 1, I have shown a fragment of a piston 1 which is provided with the usual piston ring grooves 2. Numeral 3 represents a pistonring which has a plurality of grooves I on the inner surface thereof. Between the inner surface of the ring 3 and the bottom of groove 2, I provide a cork liner 5, all as explained in the above referred to patent.

In order to form the cork strip into the proper size and shape, I subject it to the influence of pressure and heat, and for the purpose of making it non-absorbtive of moisture, I impregnate it with certain moisturerepellent substances, all in the manner which I will now describe.

The cork strip is originally of a rectangular cross section as indicated in Fig. 4, and must be reduced in size and changed in shape until it resembles the section shown in Fig. 3. In order to compresss the cork strip and change its shape. I provide a mould, which consists of a steel bar 6 having a rectangular room 7 cut lengthwise thereof; this groove is substantially the same width as the piston ring grooves 52, and of any suitable depth. (.ooperating with the groove 7 and forming the male part of the mould or die is a rectangular bar 8 (Fig. 8) whose lower side is grooved in the same way as the inside of the ring 3. At the ends of groove 7, I provide stops 9 which engage the lower side of the male plunger member 8 and limit its downward movement, whereby the cork is compressed to the desired thickness. The distance between the inner edges of the stops 9 is equal to the length of cork strip desired.

In Fig. 8 Ihave shown a cross section of my mould in operation. The female part of the mould rests upon a Support 10, and a member 11. which is movable with respect to the support 10, rests on the male member 8. Member 11 may be moved by suitable means so as to force the plunger 8 into the groove 7 and compress the cork.

In treating my cork, I take a strip of the shape shown in Fig. 4 and I dip it into a bath of motor oil of 600 degree fire test, after which I immerse it in a bath of paraflin, or the oil and paraflin may be heated and mixed in the proportions of one part of oil and two of paraffin, and the cork immersed in this liquid mixture. The cork strip is then placed in the groove 7 of the female part of the mould, and then the plunger member 8insorted over the cork strip. Pressure is then applied to the plunger 8 until the cork is compressed to the desired degree, after which the mould is placed in a suitable oven and subjected to heat. The mould and contents should be subjected to a degree of heat that will cause it to retain its shape and that preferably is somewhat higher than that to which the cork will be subjected in actual operation. I have found that if the mould is raised to a temperature between 450 and 700 degrees Fahrenheit, the desired results will be attained. The cork is then preferably left in the mould until it is cooled, when it is removed.

I find that cork which has been subjected to the above treatment will retain its size and shape even in very damp climates, and that the cork after the treatment still -retains its resiliency. The oil and parafiin form a coatin on the cork which prevents it from absorbing moisture from the air, and

therefore enables it to retain the size and shape which was imparted -to it during the treatment. With cork strips treated as above, the piston rings can be applied almost as easily as if no lining were used, and the rings will not bind after the pistons are inserted into the cylinders.

Although I have pointed out a. particular use to which the cork treated as described can be ut, this is b no means the only use to whic i I contempl ate putting the cork so treated, as it is equally adapted for various other purposes, as for example, in a packing box or for washers, gaskets or any other 'places where dense and resilient cork prod fore the cork is put into place between the piston ring and the piston, whereby an article of manufacture is produced which is of the proper size and shape for the use for which it is intended.

2. The method of treating cork so as to cause it to retain its size and shape, which comprises immersin said cork in a bath of motor oil and para in, placing said cork in a mould and applyingv pressure thereto, whereby it is compressed to the desired shape and size, subjecting the cork while under pressure to a temperature of between 450 and 700 degrees Fahrenheit.

3. The method of treating cork so as to make it moisture-repellent and cause it to retain its shape and size, which consists of applying oil to the cork, applying paraflin thereto, placing the cork in a mould, applying pressure to the cork whereby it is com- )ressed to the desired size and shape, and

eating the cork while under pressure to a temperature of between 450 and 700 degrees shape, and sinjeeted to a temperature between 450 and 700 degrees Fahrenheit,

In testimony whereof I aflix'my signature.

WILLIAM E. .oo HAeAiN.

Certificate of Correction.

It is hereby certified that the name of the patentee in Letters P atent No.1,439,869, granted December 26, 1922, for an improvement in Method of Treating Cork, was erroneously written and printer] as iWilliam E. Co Hagan, whereas said name should have been written and printed as William E. O'oHagen; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Offioe.

Si ed and sealed this 23d day. of January, A. D., 1923.

gm] 7 KARL FENNING,

Acting Commissioner of Patents. 

